The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion (IC) engines combust air and fuel within cylinders to produce drive torque. Air flow into an engine may be regulated via a throttle valve. A fuel control system controls fuel injection amount and timing. Increasing the amount of air and fuel provided to the cylinders generally increases the torque output of the engine.
Spark ignition direct injection (SIDI) systems are currently used by many engine manufacturers. SIDI refers to direct injection of highly pressurized fuel into cylinders of a spark-ignited gasoline engine. SIDI allows for improved control of fuel injection timing. A fuel system of an SIDI engine may include a low-pressure fuel pump and a high-pressure fuel pump. The low-pressure fuel pump pumps fuel from a fuel tank to a low-pressure fuel line. The high-pressure fuel pump, which is mechanically driven by the engine, pumps fuel from the low-pressure fuel line to a high-pressure fuel line and/or fuel rail. Fuel injectors of the SIDI engine receive fuel from the fuel rail and inject fuel directly into cylinders of the SIDI engine.
In an SIDI engine, fuel may be directly injected into cylinders of the SIDI engine at various times during a combustion cycle. This is unlike port-fuel-injected engines where fuel is injected, for example, into a port and/or intake manifold of an engine and before an intake stroke of a corresponding combustion cycle. The increased control that may be associated with an SIDI engine provides increased horsepower, reduced emissions, and knock suppression. The stratified fuel charge allows for a lean burn and improves fuel efficiency.